Compare what you can do without the self-imposed restrictions though. 250 turns is long enough to completely finish out the Tech Web, get all Affinities to 16+ and probably even simultaneously trigger all victory conditions.
That mainly because of Trade Routes.
So while ARC fits well with OCC (because Covert Ops don't scale to number of cities), and Covert Ops are very useful in general, they hardly compare to the utility of Trade Routes. (Polystralia also will do well in OCC, it will be interesting to see which is faster.)
Just like how every sponsor has spies, every sponsor also has trade routes.
ARC doesn't scale off number of cities, but neither does Polystralia.
If you have 1 city, Polystralia has 66% more trade routes, but does not have the option for the overpowered internal trade routes.
If you have 4 or more cities, Polystralia's bonus is less than 20% more trade routes.
Meanwhile, ARC still has 25% faster ops and an easier time maintaining intrigue.